Goose hunters often set out a collection of decoys. If the decoys are properly made and arranged, geese flying overhead may be attracted to the area. A proper, natural-looking arrangement of decoys, however, requires that some geese in the flock have their heads and necks lowered, in a "feeding position," to emulate geese gathering food from the surface of the ground or water. A smaller portion of the flock should have their heads and necks raised well above their bodies, in a "sentry position", resembling geese that are looking for indications of danger.
Most decoys, however, only portray geese in a single position. Thus, the decoy manufacturers must make and sell two different types of decoys: both "feeders" and "sentries." Consequently, there are fewer economies of scale for the manufacturer than if only one type of decoy was necessary. Thus, the price of decoys is increased.
Moreover, hunters in the field may wish to vary the positions of decoys in the feeder and sentry positions. With single-position decoys, however, a hunter in the field may not easily change the feeder/sentry proportions. To change the makeup of the decoy flock, the hunter must be willing to either decrease the size of the decoy gaggle or to bring extra decoys into the field with him.